Microsoft Corp., AOL and Yahoo! teamed up on Wednesday to offer advertisers the ability to buy non-reserved online display inventory from all three company’s.

Agencies will still have the ability to choose who they partner with (Yahoo! Network Plus, AOL’s Advertising.com and the Microsoft Media Network) while buying premium display inventory at scale to reach the customer base they choose.

By partnering together the company’s hope to increase demand for their premium networks therefore increasing cost while providing better yield for publishers and advertisers.

“We’re thrilled to partner with Microsoft and AOL and bring to market what we believe will be a more efficient, effective and more effortless way to access true premium inventory and formats,” and “There has a been a significant shift in how inventory is bought and sold, and we’re now 100 percent focused on controlling our own destiny, working directly with marketers and agencies and driving better returns for our advertising partners.”

Also commenting on the deal was Microsoft Advertising Business Group corporate vice president Rik van der Kooi who said:

“Enhancing choice and scale in today’s display advertising market is ‘a rising tide that lifts all boats’,” and “This partnership will create an opportunity where advertisers and publishers alike can benefit from easier access to — and demand for — high-quality inventory. The fact that we’re joining together to offer this kind of access to quality — yet each with our own differentiated ad offerings — is something that will benefit the market as a whole.”

Echoing the sentiments of his partners Ned Brody chief revenue officer at AOL said he’s hoping advertisers will be able to receive scaled solutions across multiple premium publishers which in turn will help “reduce friction in the marketplace.” AOL’s Advertising.com network already had agreements in place with Yahoo! and Microsoft.

The new partnerships were formed under a nonexclusive agreement which means each company will continue to make their own decisions including how they control their ad networks, how they operate ad exchanges and other aspects of their display businesses.

The partnership is being tested in the United States at this time and could expand should it become a success.